Mana produced by Jaya’s first ability can be spent among any number of instant and/or sorcery spells.

4/27/2018

You choose how many cards to discard while Jaya’s second ability is resolving. You can choose to discard zero cards this way (and then draw zero cards) if you wish.

4/27/2018

Jaya’s emblem doesn’t grant you permission to do anything with instant and sorcery cards in your graveyard except cast them. For example, you can’t cycle instant or sorcery cards with cycling from your graveyard.